I heard of the mod wherein enemies could finnaly chase you through cells.. but it required MWSE and I'm not really fond of going to use the utility.
And well... just a few minutes ago I thought of an alternative for people not using MWSE. Well mayby it already exists or isn't possible in that case I'm sorry.
I'm not a scripter myself neither do I get how to use it. But I thought that it could be an idea that we just do the completly opposite.
Instead that you're enemies follow you through cells during combat. You could restrict the player from going through cells while they are in combat. It sounds really simple so I thought this could be made without MWSE. But I don't know..
Hopefully the Idea is possible..